Tunneling spectroscopy has been performed on Bi2Sr2CaCu2O8+delta/Bi2Sr2YCu2O8+delta/Bi2Sr2CaCu2O8+delta trilayers deposited with a DC sputtering system in pure oxygen plasma. The conductance curves show either flat or linear increasing backgrounds, on which gap-like features are superimposed. The observation of the superconducting structures is consistent with the opening of the energy gap observed at the Bi2Sr2CaCu2O8+delta T-c in the zero-bias conductance measurements as a function of temperature. Zero-bias anomalies are also present in the tunneling spectra. These have been commented in the framework of the Appelbaum theory, as well as with respect to a possible d-wave symmetry of the order parameter.

Tunneling spectroscopy has been performed on Bi2Sr2CaCu2O8+delta/Bi2Sr2YCu2O8+delta/Bi2Sr2CaCu2O8+delta trilayers deposited with a DC sputtering system in pure oxygen plasma. The conductance curves show either flat or linear increasing backgrounds, on which gap-like features are superimposed. The observation of the superconducting structures is consistent with the opening of the energy gap observed at the Bi2Sr2CaCu2O8+delta T-c in the zero-bias conductance measurements as a function of temperature. Zero-bias anomalies are also present in the tunneling spectra. These have been commented in the framework of the Appelbaum theory, as well as with respect to a possible d-wave symmetry of the order parameter.